open deck & close deck.. are u reffering to VTEC? SUBARU? ETC ETC?
* im using H22A Dohc VTEC. so my engine is = CLOSE DECK
*closed deck allows for sleeve support...essentially making a stronger bottom end.
* close deck is more reliable.
Open deck means that there is a water jacket between the cylinder walls and the block. Pros are better cooling. Cons are weaker cylinder walls.
Closed deck means it's solid between the block and the sleeves. Pros and cons are the opposite of open deck
CLOSE DECK
OPEN DECK
* as i know. if OPEN DECK = its you might can or cannot change the "SLEEVES" (might be hard,coz the rounding is bigger)
* as i know. if CLOSE DECK = its easy to change the "SLEEVES" (you can put forged pistons,bigger pistons sizes n rings,change to strong "SLEEVES".
just check the pics.. hope u get what i mean.
Please see below pic. this is Subaru EJ25. (this one not change SLEEVE,but filling in the blocks with billet aluminum using a special zero tolerance fit.)
before:
after filling:
1) There is nothing about a closed-deck block that would cause cooling problems. Honda uses an open-deck design for production/casting reasons, not just engineering reasons. It saves time and money during manufacturing.
2) Closed-deck blocks are also SIGNIFICANTLY more rigid than open-deck blocks.
3) If someone has had cooling problems with a block guard, I feel strongly that it was due to a poorly designed or poorly installed block guard, rather than any fundamental flaw in the closed-deck design.